我正在研究一个示例代码 - hello world portlet。我的maven clean和maven安装很干净。但是在运行时，portlet给出了以下错误。有人可以帮助我。
12:10:08,430 WARN [org.jboss.modules] (http-localhost-127.0.0.1-8080-4) Failed to define class net.codejava.spring.config.MvcConfiguration in Module "deployment.SpringMvcFormExample.war:main" from Service Module Loader: java.lang.UnsupportedClassVersionError: net/codejava/spring/config/MvcConfiguration : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method) [rt.jar:1.6.0_24]
.....
12:10:08,588 WARN [org.jboss.modules] (http-localhost-127.0.0.1-8080-4) Failed to define class net.codejava.spring.controller.RegisterController in Module "deployment.SpringMvcFormExample.war:main" from Service Module Loader: java.lang.UnsupportedClassVersionError: net/codejava/spring/controller/RegisterController : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method) [rt.jar:1.6.0_24]
.....
12:10:08,851 WARN [org.jboss.modules] (http-localhost-127.0.0.1-8080-4) Failed to define class net.codejava.spring.config.MvcConfiguration in Module "deployment.SpringMvcFormExample.war:main" from Service Module Loader: java.lang.UnsupportedClassVersionError: net/codejava/spring/config/MvcConfiguration : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method) [rt.jar:1.6.0_24]
......
12:10:09,934 ERROR [org.springframework.web.servlet.DispatcherServlet] (http-localhost-127.0.0.1-8080-4) Context initialization failed: java.lang.IllegalStateException: Cannot load configuration class: net.codejava.spring.config.MvcConfiguration
......
12:10:10,958 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/SpringMvcFormExample]] (http-localhost-127.0.0.1-8080-4) StandardWrapper.Throwable: java.lang.IllegalStateException: Cannot load configuration class: net.codejava.spring.config.MvcConfiguration
...........
12:10:11,077 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/SpringMvcFormExample].[SpringDispatcher]] (http-localhost-127.0.0.1-8080-4) Allocate exception for servlet SpringDispatcher: java.lang.ClassNotFoundException: net.codejava.spring.config.MvcConfiguration from [Module "deployment.SpringMvcFormExample.war:main" from Service Module Loader]
................
12:10:14,561 WARN [org.jboss.as.ee] (MSC service thread 1-2) JBAS011006: Not installing optional component org.springframework.web.context.request.async.StandardServletAsyncWebRequest due to exception: org.jboss.as.server.deployment.DeploymentUnitProcessingException: JBAS011054: Could not find default constructor for class org.springframework.web.context.request.async.StandardServletAsyncWebRequest
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